Here are some places/functions that use a file dialog.
- ViewManager.py: ViewManager.__openFiles()
- Project.py: Project.openProject()
There are many more. They all use E5FileDialog..., which wraps QFileDialog...

In latest version of WSL (windows subsystem for linux) its possible to access file system of linux environment via \\wsl$\ path (logically its located under network).
From some reason eric (latest version) fails to open this path .
error screenshot attached.
For reference, it works from explorer and notepad